For director Rian Johnson, who also wrote the screenplay, interacting with Hamill was an out of this world experience.

“It took a long time before I could have a conversation with him without every five seconds that voice in the back of my head saying 'It's Luke Skywalker you're talking to',” said Johnson.

Oscar Isaac said the movie may have been the biggest yet, but director Johnson never let the actors feel overwhelmed.

"The sets were so sprawling and epic and you find yourself sometimes you feel dwarfed by all the things that you see around you, all the toys, the massive crew. But then you have someone like Rian Johnson who makes it feel so small and I think that's the other thing," said Isaac. " You have the juxtaposition of this massive thing but it also feels so intimate and that's really because of Rian. He found a way to not only work with us in a very intimate way but have that translate onto the screen."

Laura Dern has been on all kinds of movie and TV sets but she says she experienced something new on the lavish Last Jedi sets.

“It was insane,” she said. “I mean I open my eyes and there are all of the characters I have grown up loving.”

Among those characters is, of course, Princess Leia, as played by Carrie Fisher, who died shortly after filming her scenes.

“She was the life of any party and any film set,” said Johnson. “Carrie was the bright shining center of it. She gives a beautiful, beautiful performance in it this movie. And obviously we didn't know this was going to be a farewell performance when we were shooting it, but I think there are moments that are going to mean a lot to the fans. I hope so. They mean a lot to me.”